This invention relates generally to ultrasound systems and, more particularly, to a motor driver for controlling ultrasound probes for ultrasound imaging systems, especially portable ultrasound medical imaging systems.
Ultrasound systems typically include ultrasound scanning devices, such as ultrasound probes having transducers that allow for performing various ultrasound scans (e.g., imaging a volume or body). The ultrasound probes are typically connected to an ultrasound system for controlling the operation of the probes. The probes include a scan head having a plurality of transducer elements (e.g., piezoelectric crystals), which may be arranged in an array. The ultrasound system drives the transducer elements within the array during operation, such as during a scan of a volume or body, which may be controlled based upon the type of scan to be performed. In addition to electrically driving the transducer elements, the ultrasound system also may control mechanical movement of the transducer elements within the probe. The ultrasound system may include a plurality of channels for communicating with the probe. For example, the channels may transmit pulses for driving the transducer elements and for receiving signals therefrom. Additionally, control signals may be used to control the mechanical movement of the transducer array within the probe.
In volume probes, for example three-dimensional (3D) or four-dimensional (4D) probes, wherein the scan head moves during scan operation, and more particularly, wherein the transducer elements move, a motor controller is used to control the movement of the transducer elements within the scan head. For example, the motor controller may control the swinging or rotating of the transducer elements about an axle within the scan head based on signals received from the ultrasound system. The motor controller controls the translation of power from a motor to the scan head to control movement of the transducer elements.
Portable ultrasound systems, which have increasingly smaller footprints, often include an entire ultrasound system (e.g., processing components, etc.) embodied within a housing having the dimensions of a typical laptop computer or smaller. An ultrasound probe is connected to the portable ultrasound system, which then controls the probe to perform an ultrasound scan. Because of the smaller size of a portable ultrasound system, space for the various components can be more limited. Accordingly, system components may have to be implemented in smaller areas, which can result, for example, in having less processing or storage capabilities, thereby possibly reducing the performance of the overall system. Moreover, portable systems may also have other limitations, such as power and heat constraints. For example, because a portable system may run for extended periods of time on battery power, more efficient or decreased power consumption is often desirable in order to increase the time of use between battery charges. Additionally, the heat generated within smaller portable systems by the various components can also decrease the performance of the overall system. Thus, heat dissipation, or reduction of heat generation by the various components, is important.
Additionally, in volume probes having moving transducer arrays, a significant amount of power is needed and consumed by the motor and motor controller in order to move the transducer array within the scan head. Thus, as the amount of available power decreases, for example, in portable systems using battery power instead of 120 volt power wall supplies, large consumers of power, such as the motor controller, can decrease the useful operation of the system between charges. In addition, the power provided by a battery may also be insufficient to operate the motor. Moreover, known linear motor controllers or drivers are large, such that the reduced footprint of portable ultrasound systems cannot accommodate these linear motors controllers or drivers because of the space required for other components (e.g., processors, beamformers, power supplies, user interfaces, etc.). Additional space can also be needed for cooling components, e.g., to cool the motor controller or driver.